The 'M' block bottom middle of the picture looks like it's got the chemical symbol for Potassium along with its number and atomic weight. I don't know what other symbols might be on the other sides but I'm hoping one of them is Krypton.

Interesting to watch the meme propagation -- you're usually very early in the chain, but this showed up on a friend's LJ about a week ago. I was able to snag a set then (4 were left at the time); my husband better like them, or out on the curb with him...